2,767 research outputs found
Adaptation and Resilience of Interdependent Infrastructure Systems: a Complex Systems Perspective
The effects of disruption upon one or more components in interdependent infrastructure systems and the ability of
the system to return to normal operations, is investigated in this paper. This addresses the concept of resilience, and
examines the trade-off between redundancy and efficiency, as well as the adaptive ability of a system to respond to
disruptions and continue to operate, albeit not necessarily as it did initially
Intraspecific sexual competition in the clonal gynodioecious herb Glechoma hederacea in response to patchy nutrient distribution
Plants have developed numerous strate- gies to maximise resource uptake in response to the highly heterogeneous resource distribution in soils. Clonal growth enables plants to scavenge larger surfaces, potentially maximising nutrient acquisition by selectively growing in nutrient-rich patches. How- ever, the production of clonal units put plants into higher intraspecific competition. In gynodioecious clonal plants, genders usually exhibit sexual dimorphism in several growth and life history traits, but whether the genders have different competitive abilities and whether these are affected by nutrient distribution is underexplored. Here, we investigated whether the genders of Glechoma hederacea have different competitive abilities and whether these are affected by soil nutrient distribution using a greenhouse pot experiment. Female and hermaphrodite ramets were grown either alone or in competition with the same or the opposite gender in two different soil nutrient distributions for four months. Our results show that competition was the strongest factor affect- ing biomass accumulation and allocation. Females and hermaphrodites showed little sexual dimorphism in total biomass accumulation, but they differed in how they allocated this biomass between roots and shoots and in their clonal growth strategies in response to soil nutrient distribution. Taken together, our results indicate that soil nutrient distribution affects the competitive abilities of G. hederacea in a gender- specific manner. In the field, these differences would determine the structure and the dynamics of the two genders within the populations
SWI/SNF-like chromatin remodeling factor Fun30 supports point centromere function in S. cerevisiae
Budding yeast centromeres are sequence-defined point centromeres and are, unlike in many other organisms, not
embedded in heterochromatin. Here we show that Fun30, a poorly understood SWI/SNF-like chromatin remodeling factor
conserved in humans, promotes point centromere function through the formation of correct chromatin architecture at
centromeres. Our determination of the genome-wide binding and nucleosome positioning properties of Fun30 shows that
this enzyme is consistently enriched over centromeres and that a majority of CENs show Fun30-dependent changes in
flanking nucleosome position and/or CEN core micrococcal nuclease accessibility. Fun30 deletion leads to defects in histone
variant Htz1 occupancy genome-wide, including at and around most centromeres. FUN30 genetically interacts with CSE4,
coding for the centromere-specific variant of histone H3, and counteracts the detrimental effect of transcription through centromeres on chromosome segregation and suppresses transcriptional noise over centromere CEN3. Previous work has shown a requirement for fission yeast and mammalian homologs of Fun30 in heterochromatin assembly. As centromeres in budding yeast are not embedded in heterochromatin, our findings indicate a direct role of Fun30 in centromere chromatin by promoting correct chromatin architecture
Phase-shift calculation using continuum-discretized states
We present a method for calculating scattering phase shifts which utilizes
continuum-discretized states obtained in a bound-state type calculation. The
wrong asymptotic behavior of the discretized state is remedied by means of the
Green's function formalism. Test examples confirm the accuracy of the method.
The scattering is described using realistic nucleon-nucleon
potentials. The and phase shifts obtained in a single-channel
calculation are too small in comparison with experiment. The phase
shifts are in reasonable agreement with experiment, and gain contributions both
from the tensor and central components of the nucleon-nucleon potential.Comment: 16 pages, 5 figure
Age group, location or pedagogue: factors affecting parental choice of kindergartens in Hungary
Hungary has experienced significant political, economic, demographic and social changes since the end of Soviet domination in the 1990s. The gradual move towards liberal-democracy has been accompanied by growing emphasis on individualism, choice and diversity. Universal kindergarten provision for 5-6 year olds is a long established feature of the Hungarian education system, but little is known about parental choice (Török, 2004). A case study (Yin, 2004) of factors influencing parental choice and satisfaction was undertaken in one Hungarian town. This was based on a survey of 251 parents of children attending both mixed-age and same-age groups across 12 kindergartens. Parents suggested that the most important influences were geographical location and the individual pedagogue(s). Given that traditionally each pedagogue follows ‘their’ cohort from kindergarten entry to primary school, their influence appears heightened. Although generally satisfied with their chosen arrangement, parents from same-age groups expressed significantly more confidence and satisfaction, particularly in relation to cognitive development and preparation for school. Parents appear less convinced about the trend towards mixed-age groups and questions are raised about sufficiency of evidence of their benefits in a Hungarian context and the driving factors behind change
VHMPID: a new detector for the ALICE experiment at LHC
This article presents the basic idea of VHMPID, an upgrade detector for the
ALICE experiment at LHC, CERN. The main goal of this detector is to extend the
particle identification capabilities of ALICE to give more insight into the
evolution of the hot and dense matter created in Pb-Pb collisions. Starting
from the physics motivations and working principles the challenges and current
status of development is detailed.Comment: 4 pages, 6 figures. To be published in EPJ Web of Conference
An international reproducibility study validating quantitative determination of ERBB2, ESR1, PGR, and MKI67 mRNA in breast cancer using MammaTyper (R)
Background: Accurate determination of the predictive markers human epidermal growth factor receptor 2 (HER2/ERBB2), estrogen receptor (ER/ESR1), progesterone receptor (PgR/PGR), and marker of proliferation Ki67 (MKI67) is indispensable for therapeutic decision making in early breast cancer. In this multicenter prospective study, we addressed the issue of inter- and intrasite reproducibility using the recently developed reverse transcription-quantitative real-time polymerase chain reaction-based MammaTyper (R) test. Methods: Ten international pathology institutions participated in this study and determined messenger RNA expression levels of ERBB2, ESR1, PGR, and MKI67 in both centrally and locally extracted RNA from formalin-fixed, paraffin-embedded breast cancer specimens with the MammaTyper (R) test. Samples were measured repeatedly on different days within the local laboratories, and reproducibility was assessed by means of variance component analysis, Fleiss' kappa statistics, and interclass correlation coefficients (ICCs). Results: Total variations in measurements of centrally and locally prepared RNA extracts were comparable; therefore, statistical analyses were performed on the complete dataset. Intersite reproducibility showed total SDs between 0.21 and 0.44 for the quantitative single-marker assessments, resulting in ICC values of 0.980-0.998, demonstrating excellent agreement of quantitative measurements. Also, the reproducibility of binary single-marker results (positive/negative), as well as the molecular subtype agreement, was almost perfect with kappa values ranging from 0.90 to 1.00. Conclusions: On the basis of these data, the MammaTyper (R) has the potential to substantially improve the current standards of breast cancer diagnostics by providing a highly precise and reproducible quantitative assessment of the established breast cancer biomarkers and molecular subtypes in a decentralized workup.Peer reviewe
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Multi-ancestry study of blood lipid levels identifies four loci interacting with physical activity.
Many genetic loci affect circulating lipid levels, but it remains unknown whether lifestyle factors, such as physical activity, modify these genetic effects. To identify lipid loci interacting with physical activity, we performed genome-wide analyses of circulating HDL cholesterol, LDL cholesterol, and triglyceride levels in up to 120,979 individuals of European, African, Asian, Hispanic, and Brazilian ancestry, with follow-up of suggestive associations in an additional 131,012 individuals. We find four loci, in/near CLASP1, LHX1, SNTA1, and CNTNAP2, that are associated with circulating lipid levels through interaction with physical activity; higher levels of physical activity enhance the HDL cholesterol-increasing effects of the CLASP1, LHX1, and SNTA1 loci and attenuate the LDL cholesterol-increasing effect of the CNTNAP2 locus. The CLASP1, LHX1, and SNTA1 regions harbor genes linked to muscle function and lipid metabolism. Our results elucidate the role of physical activity interactions in the genetic contribution to blood lipid levels
Integrated acoustic immunoaffinity-capture (IAI) platform for detection of PSA from whole blood samples.
On-chip detection of low abundant protein biomarkers is of interest to enable point-of-care diagnostics. Using a simple form of integration, we have realized an integrated microfluidic platform for the detection of prostate specific antigen (PSA), directly in anti-coagulated whole blood. We combine acoustophoresis-based separation of plasma from undiluted whole blood with a miniaturized immunoassay system in a polymer manifold, demonstrating improved assay speed on our Integrated Acoustic Immunoaffinity-capture (IAI) platform. The IAI platform separates plasma from undiluted whole blood by means of acoustophoresis and provides cell free plasma of clinical quality at a rate of 10 uL/min for an online immunoaffinity-capture of PSA on a porous silicon antibody microarray. The whole blood input (hematocrit 38-40%) rate was 50 μl min(-1) giving a plasma volume fraction yield of ≈33%. PSA was immunoaffinity-captured directly from spiked female whole blood samples at clinically significant levels of 1.7-100 ng ml(-1) within 15 min and was subsequently detected via fluorescence readout, showing a linear response over the entire range with a coefficient of variation of 13%
The Prethalamus Is Established during Gastrulation and Influences Diencephalic Regionalization
The vertebrate neural plate contains distinct domains of gene expression, prefiguring the future brain areas. In this study, we draw an extended expression map of the rostral neural plate that reveals discrete domains inside the presumptive posterior forebrain. We show, by fate mapping, that these well-defined cell populations will develop into specific diencephalic regions. To address whether these early subterritories are already committed to restricted identities, we began to analyse the consequences of ablation and transplantation of these specific cell populations. We found that precursors of the prethalamus are already specified and irreplaceable at late gastrula stage, because ablation of these cells results in loss of prethalamic markers. Moreover, when transplanted into the ectopic environment of the presumptive hindbrain, these cells still pursue their prethalamic differentiation program. Finally, transplantation of these precursors, in the rostral-most neural epithelium, induces changes in cell identity in the surrounding host forebrain. This cell–non-autonomous property led us to propose that these committed prethalamic precursors may play an instructive role in the regionalization of the developing diencephalon
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